1. Field of the Invention
The present invention generally relates to an easy-to-start motor and a base thereof and, more particularly, to a motor that has an outstanding electromagnetic shielding effect and that is able to prevent itself from stopping at a dead location where it is difficult to start the motor, as well as a base thereof.
2. Description of the Related Art
FIG. 1 shows a structure for fixing a printed circuit board in a miniaturized motor disclosed by Taiwan Patent Application No. 96108993. Structure 9 includes a base 91 and a printed circuit board 92. A shaft tube 911 is mounted on a center of base 91. Base 91 further includes a plurality of recesses 912 and a plurality of positioning posts 913 surrounding shaft tube 911. A sensing plate 914 is mounted in each recess 912. Printed circuit board 92 is fitted around shaft tube 911 and securely mounted on base 91, thereby pressing sensing plates 914. Structure 9 can be installed in a motor to position the rotor of the motor in a proper location, allowing the motor to be started easily through the use of sensing plates 914.
Disadvantageously, it is required to arrange recesses 912 in order to receive sensing plates 914. Due to the arrangement of recesses 912, base 91 has a smaller thickness where recesses 912 are arranged, affecting the overall structural strength of base 91.
In addition, it is still required to mount the plurality of positioning posts 913 on base 91 in order for printed circuit board 92 to be securely mounted on base 91 and to firmly press sensing plates 914, preventing sensing plates 914 from disengaging from base 91. However, the plurality of positioning posts 913 is liable to crack or break after printed circuit board 92 is positioned thereon for a long duration of time. As a result, the plurality of positioning posts 913 is no longer able to effectively support printed circuit board 92. Disadvantageously, printed circuit board 92 is not able to prevent the disengagement of sensing plates 914 from base 91. Thus, structure 9 is not able to provide a secure fixing effect for sensing plates 914.
Since base 91 is made of plastic material in injection molding, base 91 is not able to provide an electromagnetic shielding effect when structure 9 is installed in an electronic device. Although sensing plates 914 are made of metal, the ability of sensing plates 914 to block electromagnetic fields is insufficient. As a result, the electromagnetic field generated during the operation of structure 9 could affect the operations of the electronic elements in the electronic device, leading to an unstable operation of the electronic device.